Naim Nait5i + squeezbox problem

[Banfi T.]

Hi folks!

A fellow hi-fi enthusiast encountered a problem with a Naim Nait5i and a Squeezbox 3. Connecting them together results to a stable humming. Other amplifiers do not react this way to the squeezbox.

We searched for an answer and the most definitve one we got suggested that the problem could be, that the Nait makes the signal ground to earth connection in the CD player (e.g in a cd5i) through the DIN cable. Also, it was suggested that SB3 does not has such earth connection, therefore the hum.

Since the Naim kit is not that cheap I would not like to play blindly with it, but logic suggest that there should be a way to make a DIN/RCA cable which internally establish this connection. However I don't know the pins of the DIN used by Naim.

Also, if there is some experience regarding the matter (or the Naim groundig scheme), please share it with us.

Thanks...

[richie00boy]

If the Squeezebox does not have a mains earth connection, then the problem cannot be a mains earth loop.

[Banfi T.]

In my understanding the problem is, that the Naim amplifier itself does not make any connection between the signal and the mains earth ground, therefore it is likely to be an earth ground problem.

[richie00boy]

To form a current loop, there must be a connection of low to medium resistance. If the Squeezebox is not connected to mains earth not one picoamp of current can flow therefore there cannot be a mains earth loop.

If the signal is also seperated from mains earth then there is even less likelihood of a earth loop problem even if the equipment is earthed.

[Banfi T.]

Great. So the hum does not originate from any grounding related problem.

Then, what is your suggestion?

[sedge1]

I have an older Nait 3 and SB3... No hum. I know this sounds odd, but have you tried moving the SB3 around to see if the hum goes away ? The SMPS and SB3 itself, if it is near the preamp boards on the Nait, can buzz a bit.

Cheers,

Sedge.